1. Field of the Invention
The present invention relates to a vehicle dispatching method and system. Specifically, the present invention is for dispatching multiple vehicles operating in a work area.
2. Background Information
In many different industries, such as warehousing, shipping or mining, and for different applications (e.g. material handling, fleet management, delivery, police and emergency vehicles, military, etc.), a plurality of vehicles must travel to and from multiple destination points. Due to vehicle limitations, such as cargo capacity or speed, vehicles must make many trips over a given period of time to accomplish a given objective, such as continuously transporting goods or materials to the desired destination on time. Dispatching often aids in efficiency. Vehicles and events in a work area are monitored so that vehicles can be dispatched when an event occurs that affects efficiency. For example, the object may be to maximize the amount of material hauled while minimizing operational costs. In another example, the object may be to maximize the number of deliveries over a period of time. Achieving these objectives (and therefore efficiency) becomes increasingly difficult as the number of vehicles and the number of destinations increase.
Vehicle dispatch systems dealing with multiple vehicles have been implemented in the past with limited success due to poor selection of routes or vehicles or solutions based on localized parameters, thereby limiting their applicability as generalized solutions, for example.
Linear programming methods have been used to establish a schedule for vehicles to follow, but the schedules have not been adapted to address the constantly-changing environment in real time. Other commonly-used vehicle dispatching systems use a “greedy” local search method to select a vehicle for the next task by implementing heuristic rules that select vehicles on a “first come first served” or “minimize wait time” basis. Even under this system, the set schedule must be maintained, again failing to take account of uncertain and constantly changing environments.
Thus, there exists a need for an efficient vehicle dispatching method and system that can be used to advantage in uncertain environments. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.